Bad weather? Bad wine
By Andrew Sharp
Ohio State Insights contributor
The expectations, for wine grapes, can be crushing.
A vintage stands or falls on the fruit’s quality. Soil quality, temperature, the health of the plant and summer rainfall—everything has to go just right for a grape to make a fine wine.
When it comes to the last couple of growing seasons, that’s bad news for Ohio, which boasts a $1.3 billion wine industry, and for the region in general.
“If you talk to anybody in the eastern United States, 2018 was one of the worst years in memory,” said Maria Smith, viticulture outreach specialist at the Department of Horticulture and Crop Science within The Ohio State University College of Food, Agricultural, and Environmental Sciences.
But this year is considerably better.
“2019 has been a standout year for the decade.”Maria Smith, viticulture outreach specialist, CFAES
“2019 has been a standout year for the decade,” Smith said. “Across the state, from Cincinnati to Ashtabula, it’s been phenomenal.”
September brought exactly what Ohio’s grapes needed: little rain and above-average temperatures to increase the sugar and decrease the acid content in the grapes.
Much hangs on the weather, for which grapes have stringent requirements, a sort of diva’s list of demands. They like winters without deep cold snaps—the headline-grabbing polar vortex of the past winter was much too cold for the vines in parts of the Midwest—and they prefer summers dry, but not too hot.
Too much rainfall causes a litany of ills, Smith said. Diseases can flourish in the moisture, preying on both the plants and the grapes. It’s a problem made worse when rain interferes with spraying schedules. And that’s not all: If wet weather keeps corn and soybean farmers out of their fields early in the spring, when they finally do spray herbicides, accidental drift can cause more damage to grapevines.
Later in the summer, rain just before harvest can dilute the grapes’ juice, or make them split or shrivel up.
Too much heat can also keep grapes from ripening properly. That’s a big deal. The ripening process is key in decreasing acidity, increasing sugar concentration, and metabolizing compounds that produce color, mouthfeel, flavors, and aroma, Smith said.
Both rain and heat have been a problem over the last year and a half. Ohio, and other nearby states, already get a lot of rain for a wine region. Most growing regions, Smith said, have fewer than 10 inches a year. Ohio averages about 30 to 40 inches, and last year’s rains accumulated up to 60 inches in some areas.
“The amount of rainfall we’ve had has been absolutely incredible,” Smith said.
“Almost every vineyard I’ve seen this year has had really good fruit. ”Maria Smith, viticulture outreach specialist, CFAES
Last season, that was coupled with temperatures that were too high right around harvest. Then wet weather continued into the spring and early summer of 2019, leaving vineyards hit with herbicide drift from late farming. The herbicides damaged up to 30% or 40% of vines in some cases, Smith said.
Even the most pristine vineyards Smith visited this past summer had some disease, while others may have had up to 60% or more crop loss.
Whenever things go sour, vineyards have ways of getting by until better times. Winemakers can mix previous vintages in with lesser wines—Smith said 2016 and 2017 were particularly good years—and they can also shrug and order in wine from parts of the country that had better weather.
If foul weather keeps grapes from ripening properly, or threatens to ruin the harvest, winemakers sometimes grab the grapes early, Smith said, and make them into wines that are less dependent on quality grape skins.
For example, red wines are fermented to completion with the skins, she said, which contribute to all the wine’s characteristics such as color and flavor.
Rosés are more forgiving than reds, because they are usually pressed off the skins before fermentation and depend less on the skins for their characteristics.
That’s not to say ripening doesn’t matter for a rosé or for white wines, which are also fermented without the skins. Smith said if grapes are very underripe, the wines can suffer from thin textures, sourness, and vegetable or grassy flavors. But if the grapes are only mildly immature, the wines might have a lighter color or different flavor that isn’t fatal to the quality.
So, for wine producers in this part of the country, 2018 was mostly a bust, and 2019 a smash hit.
"Often in Ohio," Smith said, "we have to make do with what each season’s weather gives us.”